Gas inflow in barred galaxies results in mass accumulation
in their centers, which can affect the shape of orbits
supporting the bar structure. Simulations of bars predict
that the bar ellipticity decreases with the mass buildup of
the center and can eventually lead to bar dissolution. We
have used CO maps from the BIMA Survey of Nearby Galaxies
(SONG) (Regan et al 2001) to investigate whether there is
observational evidence for this effect. Near-IR images
obtained by the SONG team were used to determine the bar
axes and ellipticity; the intensity profile was used to
determine the bulge diameter. The CO (1-0) emission line
observations from SONG were used to derive the rotation
curves of these galaxies using a tilted ring model to fit
the velocity maps. These rotation curves were used to
determine the ratio of the dynamical mass within the bulge
to that in the bar as a measure of the central mass
concentration. We find an apparent correlation between bar
ellipticity and central mass concentration. This is the
first observational evidence that bar ellipticity may
decrease with nuclear mass; it may indicate that the central
mass buildup in bars results ultimately in the dissolution
of the bar itself. This work is partially supported by NSF
AST 9981289.

The author(s) of this abstract have provided an email address
for comments about the abstract:
mousumi@astro.umd.edu